/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */

/*
  Part of the Processing project - http://processing.org

  Copyright (c) 2013-16 The Processing Foundation

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation, version 2.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty
  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the GNU Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General
  Public License along with this library; if not, write to the
  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  Boston, MA  02111-1307  USA
*/

package processing.data;

import java.io.*;
import java.util.HashMap;
import java.util.Iterator;

import processing.core.PApplet;


/**
 * A simple table class to use a String as a lookup for an float value.
 *
 * @webref data:composite
 * @see IntDict
 * @see StringDict
 */
public class FloatDict {

  /** Number of elements in the table */
  protected int count;

  protected String[] keys;
  protected float[] values;

  /** Internal implementation for faster lookups */
  private HashMap<String, Integer> indices = new HashMap<String, Integer>();


  public FloatDict() {
    count = 0;
    keys = new String[10];
    values = new float[10];
  }


  /**
   * Create a new lookup with a specific size. This is more efficient than not
   * specifying a size. Use it when you know the rough size of the thing you're creating.
   *
   * @nowebref
   */
  public FloatDict(int length) {
    count = 0;
    keys = new String[length];
    values = new float[length];
  }


  /**
   * Read a set of entries from a Reader that has each key/value pair on
   * a single line, separated by a tab.
   *
   * @nowebref
   */
  public FloatDict(BufferedReader reader) {
    String[] lines = PApplet.loadStrings(reader);
    keys = new String[lines.length];
    values = new float[lines.length];

    for (int i = 0; i < lines.length; i++) {
      String[] pieces = PApplet.split(lines[i], '\t');
      if (pieces.length == 2) {
        keys[count] = pieces[0];
        values[count] = PApplet.parseFloat(pieces[1]);
        indices.put(pieces[0], count);
        count++;
      }
    }
  }


  /**
   * @nowebref
   */
  public FloatDict(String[] keys, float[] values) {
    if (keys.length != values.length) {
      throw new IllegalArgumentException("key and value arrays must be the same length");
    }
    this.keys = keys;
    this.values = values;
    count = keys.length;
    for (int i = 0; i < count; i++) {
      indices.put(keys[i], i);
    }
  }


  /**
   * Constructor to allow (more intuitive) inline initialization, e.g.:
   * <pre>
   * new FloatDict(new Object[][] {
   *   { "key1", 1 },
   *   { "key2", 2 }
   * });
   * </pre>
   */
  public FloatDict(Object[][] pairs) {
    count = pairs.length;
    this.keys = new String[count];
    this.values = new float[count];
    for (int i = 0; i < count; i++) {
      keys[i] = (String) pairs[i][0];
      values[i] = (Float) pairs[i][1];
      indices.put(keys[i], i);
    }
  }


  /**
   * @webref floatdict:method
   * @brief Returns the number of key/value pairs
   */
  public int size() {
    return count;
  }


  /**
   * Remove all entries.
   *
   * @webref floatdict:method
   * @brief Remove all entries
   */
  public void clear() {
    count = 0;
    indices = new HashMap<String, Integer>();
  }


  // . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


  public class Entry {
    public String key;
    public float value;

    Entry(String key, float value) {
      this.key = key;
      this.value = value;
    }
  }


  public Iterable<Entry> entries() {
    return new Iterable<Entry>() {

      public Iterator<Entry> iterator() {
        return entryIterator();
      }
    };
  }


  public Iterator<Entry> entryIterator() {
    return new Iterator<Entry>() {
      int index = -1;

      public void remove() {
        removeIndex(index);
        index--;
      }

      public Entry next() {
        Entry e = new Entry(keys[index], values[index]);
        index++;
        return e;
      }

      public boolean hasNext() {
        return index+1 < size();
      }
    };
  }


  // . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .


  public String key(int index) {
    return keys[index];
  }


  protected void crop() {
    if (count != keys.length) {
      keys = PApplet.subset(keys, 0, count);
      values = PApplet.subset(values, 0, count);
    }
  }


  public Iterable<String> keys() {
    return new Iterable<String>() {

      @Override
      public Iterator<String> iterator() {
        return keyIterator();
      }
    };
  }


  // Use this to iterate when you want to be able to remove elements along the way
  public Iterator<String> keyIterator() {
    return new Iterator<String>() {
      int index = -1;

      public void remove() {
        removeIndex(index);
        index--;
      }

      public String next() {
        return key(++index);
      }

      public boolean hasNext() {
        return index+1 < size();
      }
    };
  }


  /**
   * Return a copy of the internal keys array. This array can be modified.
   *
   * @webref floatdict:method
   * @brief Return a copy of the internal keys array
   */
  public String[] keyArray() {
    crop();
    return keyArray(null);
  }


  public String[] keyArray(String[] outgoing) {
    if (outgoing == null || outgoing.length != count) {
      outgoing = new String[count];
    }
    System.arraycopy(keys, 0, outgoing, 0, count);
    return outgoing;
  }


  public float value(int index) {
    return values[index];
  }


  /**
   * @webref floatdict:method
   * @brief Return the internal array being used to store the values
   */
  public Iterable<Float> values() {
    return new Iterable<Float>() {

      @Override
      public Iterator<Float> iterator() {
        return valueIterator();
      }
    };
  }


  public Iterator<Float> valueIterator() {
    return new Iterator<Float>() {
      int index = -1;

      public void remove() {
        removeIndex(index);
        index--;
      }

      public Float next() {
        return value(++index);
      }

      public boolean hasNext() {
        return index+1 < size();
      }
    };
  }


  /**
   * Create a new array and copy each of the values into it.
   *
   * @webref floatdict:method
   * @brief Create a new array and copy each of the values into it
   */
  public float[] valueArray() {
    crop();
    return valueArray(null);
  }


  /**
   * Fill an already-allocated array with the values (more efficient than
   * creating a new array each time). If 'array' is null, or not the same
   * size as the number of values, a new array will be allocated and returned.
   */
  public float[] valueArray(float[] array) {
    if (array == null || array.length != size()) {
      array = new float[count];
    }
    System.arraycopy(values, 0, array, 0, count);
    return array;
  }


  /**
   * Return a value for the specified key.
   *
   * @webref floatdict:method
   * @brief Return a value for the specified key
   */
  public float get(String key) {
    int index = index(key);
    if (index == -1) {
      throw new IllegalArgumentException("No key named '" + key + "'");
    }
    return values[index];
  }


  public float get(String key, float alternate) {
    int index = index(key);
    if (index == -1) {
      return alternate;
    }
    return values[index];
  }


  /**
   * @webref floatdict:method
   * @brief Create a new key/value pair or change the value of one
   */
  public void set(String key, float amount) {
    int index = index(key);
    if (index == -1) {
      create(key, amount);
    } else {
      values[index] = amount;
    }
  }


  /**
   * @webref floatdict:method
   * @brief Check if a key is a part of the data structure
   */
  public boolean hasKey(String key) {
    return index(key) != -1;
  }


  /**
   * @webref floatdict:method
   * @brief Add to a value
   */
  public void add(String key, float amount) {
    int index = index(key);
    if (index == -1) {
      create(key, amount);
    } else {
      values[index] += amount;
    }
  }


  /**
   * @webref floatdict:method
   * @brief Subtract from a value
   */
  public void sub(String key, float amount) {
    add(key, -amount);
  }


  /**
   * @webref floatdict:method
   * @brief Multiply a value
   */
  public void mult(String key, float amount) {
    int index = index(key);
    if (index != -1) {
      values[index] *= amount;
    }
  }


  /**
   * @webref floatdict:method
   * @brief Divide a value
   */
  public void div(String key, float amount) {
    int index = index(key);
    if (index != -1) {
      values[index] /= amount;
    }
  }


  private void checkMinMax(String functionName) {
    if (count == 0) {
      String msg =
        String.format("Cannot use %s() on an empty %s.",
                      functionName, getClass().getSimpleName());
      throw new RuntimeException(msg);
    }
  }


  /**
   * @webref floatlist:method
   * @brief Return the smallest value
   */
  public int minIndex() {
    //checkMinMax("minIndex");
    if (count == 0) return -1;

    // Will still return NaN if there are 1 or more entries, and they're all NaN
    float m = Float.NaN;
    int mi = -1;
    for (int i = 0; i < count; i++) {
      // find one good value to start
      if (values[i] == values[i]) {
        m = values[i];
        mi = i;

        // calculate the rest
        for (int j = i+1; j < count; j++) {
          float d = values[j];
          if ((d == d) && (d < m)) {
            m = values[j];
            mi = j;
          }
        }
        break;
      }
    }
    return mi;
  }


  // return the key for the minimum value
  public String minKey() {
    checkMinMax("minKey");
    int index = minIndex();
    if (index == -1) {
      return null;
    }
    return keys[index];
  }


  // return the minimum value, or throw an error if there are no values
  public float minValue() {
    checkMinMax("minValue");
    int index = minIndex();
    if (index == -1) {
      return Float.NaN;
    }
    return values[index];
  }


  /**
   * @webref floatlist:method
   * @brief Return the largest value
   */
  // The index of the entry that has the max value. Reference above is incorrect.
  public int maxIndex() {
    //checkMinMax("maxIndex");
    if (count == 0) {
      return -1;
    }
    // Will still return NaN if there is 1 or more entries, and they're all NaN
    float m = Float.NaN;
    int mi = -1;
    for (int i = 0; i < count; i++) {
      // find one good value to start
      if (values[i] == values[i]) {
        m = values[i];
        mi = i;

        // calculate the rest
        for (int j = i+1; j < count; j++) {
          float d = values[j];
          if (!Float.isNaN(d) && (d > m)) {
            m = values[j];
            mi = j;
          }
        }
        break;
      }
    }
    return mi;
  }


  /** The key for a max value; null if empty or everything is NaN (no max). */
  public String maxKey() {
    //checkMinMax("maxKey");
    int index = maxIndex();
    if (index == -1) {
      return null;
    }
    return keys[index];
  }


  /** The max value. (Or NaN if no entries or they're all NaN.) */
  public float maxValue() {
    //checkMinMax("maxValue");
    int index = maxIndex();
    if (index == -1) {
      return Float.NaN;
    }
    return values[index];
  }


  public int index(String what) {
    Integer found = indices.get(what);
    return (found == null) ? -1 : found.intValue();
  }


  protected void create(String what, float much) {
    if (count == keys.length) {
      keys = PApplet.expand(keys);
      values = PApplet.expand(values);
    }
    indices.put(what, Integer.valueOf(count));
    keys[count] = what;
    values[count] = much;
    count++;
  }


  /**
   * @webref floatdict:method
   * @brief Remove a key/value pair
   */
  public int remove(String key) {
    int index = index(key);
    if (index != -1) {
      removeIndex(index);
    }
    return index;
  }


  public String removeIndex(int index) {
    if (index < 0 || index >= count) {
      throw new ArrayIndexOutOfBoundsException(index);
    }
    String key = keys[index];
    //System.out.println("index is " + which + " and " + keys[which]);
    indices.remove(keys[index]);
    for (int i = index; i < count-1; i++) {
      keys[i] = keys[i+1];
      values[i] = values[i+1];
      indices.put(keys[i], i);
    }
    count--;
    keys[count] = null;
    values[count] = 0;
    return key;
  }


  public void swap(int a, int b) {
    String tkey = keys[a];
    float tvalue = values[a];
    keys[a] = keys[b];
    values[a] = values[b];
    keys[b] = tkey;
    values[b] = tvalue;

//    indices.put(keys[a], Integer.valueOf(a));
//    indices.put(keys[b], Integer.valueOf(b));
  }


  /**
   * Sort the keys alphabetically (ignoring case). Uses the value as a
   * tie-breaker (only really possible with a key that has a case change).
   *
   * @webref floatdict:method
   * @brief Sort the keys alphabetically
   */
  public void sortKeys() {
    sortImpl(true, false, true);
  }


  /**
   * @webref floatdict:method
   * @brief Sort the keys alphabetically in reverse
   */
  public void sortKeysReverse() {
    sortImpl(true, true, true);
  }


  /**
   * Sort by values in descending order (largest value will be at [0]).
   *
   * @webref floatdict:method
   * @brief Sort by values in ascending order
   */
  public void sortValues() {
    sortValues(true);
  }


  /**
   * Set true to ensure that the order returned is identical. Slightly
   * slower because the tie-breaker for identical values compares the keys.
   * @param stable
   */
  public void sortValues(boolean stable) {
    sortImpl(false, false, stable);
  }


  /**
   * @webref floatdict:method
   * @brief Sort by values in descending order
   */
  public void sortValuesReverse() {
    sortValuesReverse(true);
  }


  public void sortValuesReverse(boolean stable) {
    sortImpl(false, true, stable);
  }


  protected void sortImpl(final boolean useKeys, final boolean reverse,
                          final boolean stable) {
    Sort s = new Sort() {
      @Override
      public int size() {
        if (useKeys) {
          return count;  // don't worry about NaN values

        } else if (count == 0) {  // skip the NaN check, it'll AIOOBE
          return 0;

        } else {  // first move NaN values to the end of the list
          int right = count - 1;
          while (values[right] != values[right]) {
            right--;
            if (right == -1) {
              return 0;  // all values are NaN
            }
          }
          for (int i = right; i >= 0; --i) {
            if (Float.isNaN(values[i])) {
              swap(i, right);
              --right;
            }
          }
          return right + 1;
        }
      }

      @Override
      public float compare(int a, int b) {
        float diff = 0;
        if (useKeys) {
          diff = keys[a].compareToIgnoreCase(keys[b]);
          if (diff == 0) {
            diff = values[a] - values[b];
          }
        } else {  // sort values
          diff = values[a] - values[b];
          if (diff == 0 && stable) {
            diff = keys[a].compareToIgnoreCase(keys[b]);
          }
        }
        return reverse ? -diff : diff;
      }

      @Override
      public void swap(int a, int b) {
        FloatDict.this.swap(a, b);
      }
    };
    s.run();

    // Set the indices after sort/swaps (performance fix 160411)
    indices = new HashMap<String, Integer>();
    for (int i = 0; i < count; i++) {
      indices.put(keys[i], i);
    }
  }


  /**
   * Sum all of the values in this dictionary, then return a new FloatDict of
   * each key, divided by the total sum. The total for all values will be ~1.0.
   * @return a FloatDict with the original keys, mapped to their pct of the total
   */
  public FloatDict getPercent() {
    double sum = 0;
    for (int i = 0; i < count; i++) {
      sum += values[i];
    }
    FloatDict outgoing = new FloatDict();
    for (int i = 0; i < size(); i++) {
      double percent = value(i) / sum;
      outgoing.set(key(i), (float) percent);
    }
    return outgoing;
  }


  /** Returns a duplicate copy of this object. */
  public FloatDict copy() {
    FloatDict outgoing = new FloatDict(count);
    System.arraycopy(keys, 0, outgoing.keys, 0, count);
    System.arraycopy(values, 0, outgoing.values, 0, count);
    for (int i = 0; i < count; i++) {
      outgoing.indices.put(keys[i], i);
    }
    outgoing.count = count;
    return outgoing;
  }


  public void print() {
    for (int i = 0; i < size(); i++) {
      System.out.println(keys[i] + " = " + values[i]);
    }
  }


  /**
   * Write tab-delimited entries out to
   * @param writer
   */
  public void write(PrintWriter writer) {
    for (int i = 0; i < count; i++) {
      writer.println(keys[i] + "\t" + values[i]);
    }
    writer.flush();
  }


  /**
   * Return this dictionary as a String in JSON format.
   */
  public String toJSON() {
    StringList items = new StringList();
    for (int i = 0; i < count; i++) {
      items.append(JSONObject.quote(keys[i])+ ": " + values[i]);
    }
    return "{ " + items.join(", ") + " }";
  }


  @Override
  public String toString() {
    return getClass().getSimpleName() + " size=" + size() + " " + toJSON();
  }
}
